Environmental Predictors of Seasonal Influenza Epidemics across Temperate and Tropical Climates

PLoS Pathogens

Cécile Viboud¹  James D. Tamerius²  Wladmir J. Alonso²  Christopher K. Uejio³  Kimberly Bloom-Feshbach³  Jeffrey Shaman³  Andrew Comrie⁴ 

[1]Department of Geography, Florida State University, Tallahassee, Florida, United States of America

[2]Environmental Health Sciences, Columbia University, New York, New York, United States of America

[3]Fogarty International Center, National Institutes of Health, Bethesda, Maryland, United States of America

[4]Mount Sinai School of Medicine, New York, New York, United States of America

关键词: Influenza;    Humidity;    Seasons;    Latitude;    Meteorology;    Solar radiation;    Influenza A virus;    Influenza viruses;   

DOI  :  10.1371/journal.ppat.1003194

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Human influenza infections exhibit a strong seasonal cycle in temperate regions. Recent laboratory and epidemiological evidence suggests that low specific humidity conditions facilitate the airborne survival and transmission of the influenza virus in temperate regions, resulting in annual winter epidemics. However, this relationship is unlikely to account for the epidemiology of influenza in tropical and subtropical regions where epidemics often occur during the rainy season or transmit year-round without a well-defined season. We assessed the role of specific humidity and other local climatic variables on influenza virus seasonality by modeling epidemiological and climatic information from 78 study sites sampled globally. We substantiated that there are two types of environmental conditions associated with seasonal influenza epidemics: “cold-dry” and “humid-rainy”. For sites where monthly average specific humidity or temperature decreases below thresholds of approximately 11–12 g/kg and 18–21°C during the year, influenza activity peaks during the cold-dry season (i.e., winter) when specific humidity and temperature are at minimal levels. For sites where specific humidity and temperature do not decrease below these thresholds, seasonal influenza activity is more likely to peak in months when average precipitation totals are maximal and greater than 150 mm per month. These findings provide a simple climate-based model rooted in empirical data that accounts for the diversity of seasonal influenza patterns observed across temperate, subtropical and tropical climates.

【 授权许可】

CC BY